Model components / Base / pretrained models

Seed-OSS

ByteDance Seed's open-weight model line, released August 2025 as 36B base and instruct checkpoints trained on 12T tokens. The instruct model targets long-context, reasoning and agentic use with a controllable thinking budget, and the base ships in with- and without-synthetic-data variants aimed at fine-tuning research.

ByteDance's open-weight counterpart to the closed doubao-seed line, and the openness contrast between the two is the org-page signal. Apache-2.0 weights with no released corpus or training pipeline; the tech report was still "coming soon" on the card at read time. Verified 2026-09-01 via the Seed-OSS-36B-Instruct card and the ByteDance-Seed/seed-oss repository.

Openness

3 high confidence

3.0

weights: open(36B Base, Base-woSyn and Instruct, ungated on HF)
data: closed(12T-token pretraining corpus not released
code: partial(ByteDance-Seed/seed-oss is inference/usage
license: Apache-2.0(OSI)

Apache-2.0 weights in all three SKUs, ungated, with the 12T-token corpus unreleased and only inference code published. The card says plainly the series is released "under the Apache-2.0 license" and that the tech report is coming; nothing about the recipe ships. Open weights, closed recipe: 3 by the fallthrough.

https://huggingface.co/api/models/ByteDance-Seed/Seed-OSS-36B-Instruct recorded 2026-09-01
`gated: false`, cardData.license `apache-2.0`, safetensors listed; 35,117 downloads in the trailing 30 days.
https://huggingface.co/ByteDance-Seed/Seed-OSS-36B-Instruct/raw/main/README.md recorded 2026-09-01
Card: "We release Seed-OSS-36B-Base (both with and without synthetic data versions) and Seed-OSS-36B-Instruct"; "Although trained with only 12T tokens"; "We release this series of models to the open-source community under the Apache-2.0 license"; a "Tech Report Coming Soon" badge and no corpus or pipeline link.
https://api.github.com/repos/ByteDance-Seed/seed-oss recorded 2026-09-01
`license: Apache-2.0`, 892 stars; the release repository, carrying no training pipeline — what holds `code` at partial.

Adoption

2 high confidence

2.0

41,913 downloads in the trailing 30 days across the two declared artifacts (Seed-OSS-36B-Instruct 35,117; Seed-OSS-36B-Base 6,796), which bands at level 2 (10K-100K) on the model adoption scale.

https://huggingface.co/api/models/ByteDance-Seed/Seed-OSS-36B-Instruct recorded 2026-09-01
35,117 downloads in the trailing 30 days for ByteDance-Seed/Seed-OSS-36B-Instruct
https://huggingface.co/api/models/ByteDance-Seed/Seed-OSS-36B-Base recorded 2026-09-01
6,796 downloads in the trailing 30 days for ByteDance-Seed/Seed-OSS-36B-Base

Capability

4 medium confidence

4.0

The strong 30B-class open-weight tier: card benchmarks put the instruct model at or ahead of same-size open peers on math and reasoning despite a smaller training budget, which is the same "best of the ~32B open class, short of the trillion-parameter frontier" reading that puts olmo at 4. Vendor-published numbers with the tech report still pending, so confidence stays medium.

https://huggingface.co/ByteDance-Seed/Seed-OSS-36B-Instruct/raw/main/README.md recorded 2026-09-01
Card benchmark tables with AIME24 91.7 for Seed-OSS-36B-Instruct against same-size open peers, plus long-context and agentic suite results; "Although trained with only 12T tokens, Seed-OSS achieves excellent performance on several popular open benchmarks".

Verified 2026-09-01